Tag: Linux

How to move disk space from LVM partition to another

Default LVM partitioning in Linux may not be optimal for some tasks. For example, root partition can be too small and filled up after some time while home partition is large and almost unused. In this case one obviously would want to transfer some amount of space from /home to / partitions. Consider the following …

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Rescue a CentOS system with GRUB

GRUB (Grand Unified Bootloader)  is the most widely used bootloader among Linux operating systems (OS) but it can boot any OS. GRUB main functionality is to allow users to select between different operating systems to boot. As bootloader GRUB is installed on the MBR (Master Boot Record) and additionally to allow us to select different …

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Disable send_redirects or NETKEY

disable-sendredirects

During the process of a VPN client configuration with xl2tpd and openswan ipsec verify command threw the following error: Disable /proc/sys/net/ipv4/conf/*/send_redirects or NETKEY will act on or cause sending of bogus ICMP redirects! To fix this we need to disable send_redirects and save changes in /etc/sysctl.conf so they will be permanent across reboots. Here is …

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10 Practical Sar Usage Examples

There are two ways to invoke sar. sar followed by an option (without specifying a saXX data file). This will look for the current day’s saXX data file and report the performance data that was recorded until that point for the current day. sar followed by an option, and additionally specifying a saXX data file …

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Generate CPU, Memory and I/O report using SAR command

SAR stands for System Activity Report, as its name suggest sar command is used to collect,report & save CPU, Memory, I/O usage in Unix like operating system. SAR command produce the reports on the fly and can also save the reports in the log files as well. In this article we will discuss different examples …

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How to Set the DSCP Flag in Windows and Linux

QoSmappingDSCP

DSCP (Differentiated Services Code Point) is a series of bits in the IP header for classification purposes. These bits specify the precedence value of the packet, the drop probability, and the network service used. Before setting the DSCP flag with a desired value, you need to take some things into consideration. You cannot force the …

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How to upload a file to remote FTPS with cURL and PHP

You may need to upload a file to remote FTP or FTPS in a number of cases. In this article I’m going to show you how to upload file with cURL from Linux shell and using cURL in PHP. Be sociable 🙂 Share!

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Change your Mail Transport Agent (MTA)

A Mail Transfer Agent (MTA) is a software that transfers electronic mail messages from one computer to another using a client server application architecture. An MTA is also called by a few other names such as – a Message Transfer Agent, Mail Relay, and Mail Transport Agent. Some of the popular MTAs in use are …

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How to install and use vnstat (Network Traffic Monitor) in Linux

vnStat is a console-based network traffic monitor for Linux and BSD that keeps a log of network traffic for the selected interface(s). It uses the network interface statistics provided by the kernel as information source. This means that vnStat won’t actually be sniffing any traffic and also ensures light use of system resources. In this …

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